Dell latitude E6540 agressive throttling

BIOS/UEFI Modding BIOS Modding Guides and Problems
1

hello good day.

i got a dell latitude e6540 laptop here

which has a core i7 4800mq and a

amd Radeon HD 8790M.

when they are working they are fine.

but once you have been using the gpu at higher than 90% for about 15 to 20 minutes it starts to throttle the cpu.

all the way down to 300mhz. which basically freezes the system in place

throttlestop says "GPU POWER" As the reason. (also seen something of "ring power" but that doesnt show up as often



photo5987830799363322190.jpg







i have a agressive downclock on the cpu already.

from 3.8 ghz to 2.3ghz with a 80mv downvolt on core and cache. but stil… it keeps pushing


i currently have 2015 amd gpu drivers on the machine since for whatever reason. anything newer refuses to engage the videocard on even the default apps it already set to "performance"


i’ve had this laptop for about 3 years now and it’s always been very iffy with it’s gpu…

i’m 300% sure this limit is not real. and just to “prevent” overheating. (which it wil do if cpu is at stock settings. )

since i got a downvolt ect temps are mostly in control.

is there anyway to stop these limits?








mind you. the gpu doesnt actually throttledown.

it just forces the cpu to run even lower than intel spec


i know this bios is fully UEFI. but i’m not 100% sure what kinda bios it is.

this bios allows downgrades. and there is a custom bios out there to aid EGPU’s by disabling the IGPU and internal DGPU

2

here’s how it looks like when throttled. gpu and cpu were both under 75/80c

photo5987830799363322194.jpg

3

Hi,
I have the same laptop and there’re also big throttle problems in my case (although the CPu is i7 4712MQ ).
One thing is that sometimes it requires that you plug/unplug it to activate the real performance mode (else the GPU stays at 300 Mhz …, probably because sleep mode stays activated after windows Sleep or throttle).
Secondly, I see that you already use ThrottleStop, I actually had the same problem as you (with underclocking the CPU), but after activating “Chipset modulation” and “Clock modulation” the CPU does not throttles anymore. Indeed in your image we can see that on the right, the “Mod” column is at 12.5%, however it should be at 100% (with “Clock modulation” ticked it should be the case) (see this thread https://forums.tomsguide.com/threads/del…ottling.384049/) .
You can also try to undervolt your CPU/ integrated GPU with throttlestop in FIVR/Unlock adjustable voltage. It can help save some watts.
I also tried ASUS GPU tweak 2 which can help undervolt your dedicated GPU too.
Concerning the drivers I managed to install the latest radeon drivers, I think you could too (but it may need to uninstall them cleanly before, see DDU). It allows you to set max FPS to stop the GPU from overheating too much (feature called “Radeon Chill”).

Hope it helps